In the related work “Experimental analysis of the aging behavior of battery packs with forced air cooling and immersed cooling system” by A. Marongiu et al. (also presented in this conference) an experimental study on a novel compact immersion cooling system for cylindrical battery cell packs based on the 3M Novec 7200 cooling fluid has been performed. Two identical battery packs composed of 25 cylindrical 18650-type cells are cycled until End-of-Life condition using different thermal management strategies, namely air cooling and active immersed cooling. While the mentioned work examines the degradation on pack level, this work focuses on analyzing single cell degradation state after pack’s disassembly. The goal is to evaluate how different pack cooling strategies and thus different temperature distributions of parallel cells in a battery pack impacts degradation on single cells when comparing the two different cooling systems. Single cell checkups have been performed before and after aging of the cells in both packs. To identify the most relevant aging processes, differential analysis, and post-mortem analysis for a selection of cells are conducted. A special focus is placed on cells which have shown different aging behavior in respect of the others. The work discusses the link of the identified aging characteristics to the presence of temperature gradients inside the battery packs due to the different applied thermal management strategies. The findings promote the understanding of the effects on single cell degradation in packs with an active immersed cooling system.